In an effort to make lightweight and low cost seats while maintaining the desired support and comfort, it has heretofore been proposed that spring assemblies be utilized that comprise a plurality of longitudinally extending wires and a plurality of transversely spaced wires wound around the longitudinally extending wires with additional longitudinally extending wires connecting the free ends of the transversely spaced wires. See, for example, U.S. Pat. Nos. 3,639,002, 3,727,980 and 3,880,467, having a common assignee with the present application.
Among the objects of the invention are to provide a seat construction utilizing similar spring assemblies having a configuration that is particularly adapted for use in making a seat back such as in the back of furniture which produces a low cost, comfortable seat back.
In accordance with the invention, the spring assembly is modified so that one of the additional longitudinally extending wires which connects the free ends of the transversely spaced wires is displaced from the plane of the remainder of the longitudinally extending wires and the portions of the transversely extending wires between the one additional longitudinally extending wire and the adjacent longitudinally extending wire are curved when the spring assembly is in the untensioned state. The spring assembly is mounted on a seat back frame with the additional longitudinally extending wires connected directly or through springs to the top and bottom rails of the seat back frame.